骨组织工程纳米复合支架及其生物学评价

目的:综述骨组织工程常用支架材料的种类及其性能,同时,简介一种新型的,可降解的,具有三维空间网络结构的纳米支架材料——细菌纤维素/羟基磷灰石复合材料,并探讨纳米生物材料的安全性评价.资料来源:检索人为第一作者,检索文献时限为1979-01/2009-06,检索数据库为PubMed数据库(http://www.ncbi.nlm.nih.gov/PubMed)及CNKI数据库(www.cnki.net/index.htm).中文检索词"骨组织工程,细菌纤维素,安全性评价";英文检索词为"bone tissue engineering,Bacterial cellulose,safety evaluation".资料选择:①文章所述内容与骨组织工程密切相关.②有关于纳米材料安全性评价的文章.结局评价指标:骨组织工程材料的种类及性能,纳米材料的安全性.结果:常用的3种支架材料有天然生物材料,人工合成高分子生物材料及陶瓷材料.单一材料难以满足组织工程所需的机械强度和生物相容性,而生理状态的磷灰石是纳米级,纳米级复合材料更符合仿生的原则.细菌纤维素与具有极好生物活性、骨传导作用和骨结合能力的纳米羟基磷灰石复合制成纤维状复合支架材料,不仅具有足够的强度,还具有骨传导功能,以满足骨细胞在支架上的黏附和繁殖,成为一种很有前途的骨组织工程纳米支架材料.对生物材料生物相容性的研究与评价,不仅要从整体水平去观察材料对人体各系统的影响,从细胞水平去观察材料对细胞的数量、形态及分化的影响,还要深入到分子水平去观察材料对细胞DNA、mRNA以及蛋白表达水平的影响.结论:由于细菌纤维素,羟基磷灰石复合支架材料结合细菌纤维素和羟基磷灰石两种材料的优点,其复合产物的性能将优于传统的骨组织工程产品.对其完成一系列生物相容性评价后,新一代骨组织工程三维纳米纤维仿生支架材料便可安全的投入到临床应用.     

纳米细菌纤维素的细胞生物相容性

背景:细菌纤维素是一种新型天然高分子材料,具有良好的三维网状结构和高持水性等独特性能。目的:观察天然高分子材料细菌纤维素与细胞共培养的生物相容性。方法:采用静置培养方案制备细菌纤维素支架,将处于对数生长期的C2C12细胞和L929细胞分别与细菌纤维素支架材料在体外共培养,采用扫描电镜观察材料微结构,倒置相差显微镜观察细胞生长及增殖情况,CCK-8比色法检测细胞增殖率。结果与结论:细菌纤维素具有精细的三维结构,纤维直径为纳米级别。C2C12细胞和L929细胞在细菌纤维素材料上可以很好地生长、增殖,细胞状态为正常的梭型,形态无明显变化;两种细胞在细菌纤维素材料上的相对增殖率均≥100%,细胞毒性为0级。说明细菌纤维素具有良好的生物相容性,对细胞黏附和增殖无影响。     

纳米羟基磷灰石/细菌纤维素复合材料及其降解物的细胞相容性评价

背景:新型复合材料纳米羟基磷灰石,细菌纤维素是一种极具应用前景的骨组织工程材料,而骨组织工程材料要求其本身及其降解产物具有良好的细胞相容性,实验在传统的MTT法评价细胞相容性的基础上,进一步应用流式细胞术的方法从DAN合成周期的角度进行评价.目的:评价新型纳米复合材料纳米羟基磷灰石/细菌纤维素及其酶降解产物的细胞相容性.方法:应用体外细胞培养法,观察纳米羟基磷灰石,细菌纤维素复合材料及其降解物对成骨细胞形态学的影响,同时采用MTT比色法评价纳米羟基磷灰石,细菌纤维素及其降解物对成骨细胞生长和增殖的影响,并尝试用流式细胞仪检测材料作用于细胞后细胞周期时相的变化,从而在分子水平上评价材料对细胞增殖的影响.结果与结论:纳米羟基磷灰石,细菌纤维素复合材料及其降解物对成骨细胞的形态无明显影响,对细胞生长和增殖无明显抑制作用.MTT细胞毒性试验显示原材料及其降解物的细胞增殖率均在80%以上,细胞毒性均为1级,材料对培养细胞无明显细胞毒性.流式细胞仪检测结果显示材料与细胞接触后能降低G_0/G_1期细胞比例,增加S,G_2/M期细胞比例,能增加成骨细胞DNA的合成,促进成骨细胞生长和组织修复.提示纳米羟基磷灰石,细菌纤维素复合材料细胞相容性良好,是一种安全的、很有应用前景的骨组织工程支架材料.     

细菌纤维素在组织工程中的应用

背景：细菌纤维素是纳米级纤维,具有许多独特的理化和机械性能及良好的生物相容性和可降解性等特性,目前已成为国际上新型组织工程材料的研究热点。 目的：分析细菌纤维素在组织工程中的应用。 方法：检索2004至2013年PubMed数据库和中国知网数据库中相关文献,英文检索词为＂bacterial cellulose; tissue engineering＂,中文检索词为＂细菌纤维素;组织工程＂。选取有关细菌纤维素在组织工程中应用方面密切相关文献48篇进行分析。 结果与结论：细菌纤维素具有高结晶度、高持水性、高机械强度、可降解性、良好的生物相容性和超细三维纳米网状纤维结构等独特特性,能作为生物活性分子的载体,维持生物活性分子的活性。同时,细菌纤维素通过改性修饰能提高其机械和生物特性,促进损伤组织的修复重建。目前已开始将细菌纤维素应用于组织器官重建中。细菌纤维素能作为生物活性分子的载体,但存在难以降解和功能单一等缺点,通过对细菌纤维素的改性修饰可以改善它的功能和促进降解。     

介孔-大孔生物活性玻璃的合成及其生物活性

背景:多孔生物活性玻璃材料具有较大的比表面积、孔隙率以及贯通的孔道结构,可以加速羟基磷灰石沉积的动力学速率从而提高材料诱导形成新骨的能力。目的:利用有机酸替代无机酸来合成新型介孔-大孔生物活性玻璃。方法:将柠檬酸和P123加入到无水乙醇中,在室温下搅拌2h至溶液澄清。依次加入正硅酸乙酯、四水硝酸钙和三磷酸乙酯,继续搅拌24h。将所得溶胶倒入培养皿中,在室温下放置7d,之后高温下烧结除去有机物模板。结果与结论:①利用有机酸所制备的材料具有大孔结构,拥有较大的比表面积、孔隙率和孔径。②合成的介孔-大孔生物活性玻璃在人工模拟体液中可以诱导形成含碳羟基磷灰石,表现出了较好的生物活性,有望成为一种具有发展前景的骨缺损修复替代材料。     

介孔-大孔生物活性玻璃的合成及其生物活性

背景：多孔生物活性玻璃材料具有较大的比表面积、孔隙率以及贯通的孔道结构,可以加速羟基磷灰石沉积的动力学速率从而提高材料诱导形成新骨的能力。目的：利用有机酸替代无机酸来合成新型介孔-大孔生物活性玻璃。方法：将柠檬酸和P123加入到无水乙醇中,在室温下搅拌2h至溶液澄清。依次加入正硅酸乙酯、四水硝酸钙和三磷酸乙酯,继续搅拌24h。将所得溶胶倒入培养皿中,在室温下放置7d,之后高温下烧结除去有机物模板。结果与结论：①利用有机酸所制备的材料具有大孔结构,拥有较大的比表面积、孔隙率和孔径。②合成的介孔-大孔生物活性玻璃在人工模拟体液中可以诱导形成含碳羟基磷灰石,表现出了较好的生物活性,有望成为一种具有发展前景的骨缺损修复替代材料。     

纳米羟基磷灰石/细菌纤维素复合组织工程支架的细胞毒性和生物相容性

背景：天津大学材料学院利用仿生学方法制备的纳米羟基磷灰石/细菌纤维素复合支架材料,具有与天然骨相似的结构和性能。目的：研究纳米羟基磷灰石/细菌纤维素复合组织工程支架的细胞毒性和生物相容性。方法：①急性全身性毒性实验：将纳米羟基磷灰石/细菌纤维素材料浸提液与生理盐水分别注射至昆明小鼠腹腔,注射24,48,72 h记录小鼠体质量。②致敏实验：在日本大耳白兔背部皮下分别注射纳米羟基磷灰石/细菌纤维素材料浸提液与生理盐水,72 h内观察注射部位水肿及红斑情况,间隔14 d后再次行激发实验。③热源实验：在日本大耳白兔耳缘静脉注射纳米羟基磷灰石/细菌纤维素材料浸提液,注射后检测体温变化。④溶血实验：在稀释的兔抗凝血中分别加入纳米羟基磷灰石/细菌纤维素材料浸提液、生理盐水与蒸馏水。⑤将第3代兔骨髓间充质干细胞与纳米羟基磷灰石/细菌纤维素材料共培养,观察材料表面细胞增殖、生长及黏附状态。结果与结论：纳米羟基磷灰石/细菌纤维素复合支架材料无急性全身毒性、无致敏性、无热源反应、无溶血反应,该支架材料具有三维网络结构,骨髓间充质干细胞在材料表面生长、增殖及黏附良好,表明纳米羟基磷灰石/细菌纤维素复合支架材料具有良好的生物相容性与细胞相容性。     

纯硅纳米孔材料AMS-8对溶菌酶的吸附和释放

背景:纳米介孔材料具有较高的比表面积、均一可调的孔径分布、规则的孔道结构和较强的吸附性能,是良好的酶固定化载体.目前对AMS材料的研究主要集中于合成和开发新材料方面,而对于生物分子的吸附、释放行为的研究还不多见.目的:筛选介孔材料AMS-8吸附释放溶菌酶的最佳条件,观察不同条件对酶吸附量及释放量的影响.方法:以阴离子表面活性剂为模板剂,3-氨丙基三甲氧基硅烷为助结构导向剂,水热法合成纯硅纳米孔材料AMS-8,结合小角度X射线粉末衍射和氮气吸附,脱附技术对合成的材料进行表征.改变酶溶液初始的浓度条件,测定吸附量的变化,在不同pH值的PBS洗脱液条件下测定释放量的变化.结果与结论:结果显示,AMS-8具有高度有序的立方孔道径结构,比表面积达到867 m2/g,孔道直径为3.4 nm.以溶菌酶为模型分子,首先观察了AMS-8在中性(pH=7)条件下,对不同质量浓度溶菌酶的吸附行为.研究发现,当溶菌酶质量浓度为0.5 g/L时,AMS-8的最大吸附量为136 mg/g.其次,观察了溶菌酶/AMS-8体系在不同pH条件下对溶菌酶蛋白的释放行为.结果表明对于溶菌酶蛋白纳米孔材料AMS-8表现出了良好的缓释效果,其中pH值对缓释行为具有良好的调控作用.     

纳米荧光碳点与细菌生物相容性的初步研究

目的用大肠埃希菌(E.coli)和金黄色葡萄球菌(S.aureus)研究新型免疫标记物——纳米荧光碳点(CDs)对此两种细菌的生物相容性。方法以洽草为材料合成CDs,通过透射电镜(TEM)﹑荧光光谱仪和傅立叶红外分析仪研究合成的CDs的特征。借助比色计和扫描电镜(SEM)观察这两种细菌分别与CDs共培养后的生长曲线,及CDs对细菌形态的影响。用傅立叶变换衰减全反式红外分析(ATR-FTIR)和荧光光谱仪分析此两种菌对CDs的直接效应。结果合成得到形态较均一的CDs。与细菌共培养的CDs对E.coli和S.aureus的生长无明显影响,但可影响细菌的形态;细菌能够黏附或吞噬一定量的CDs,并可致CDs的荧光衰减。结论 CDs对E.coli和S.aureus有一定的生物相容性,但有细胞毒性;而此两种菌对CDs荧光有非特异性猝灭作用。     

细菌纤维素膜作为创伤性敷料的可行性(英文)

背景:细菌纤维素为纳米级纤维材料,具有良好的生物相容性、湿态时高的机械强度、良好的液体和气体透过性,有利于皮肤组织生长和限制感染,有可能成为一种临时皮肤代用品和有应用潜力的生物敷料.目的:通过动物实验观察细菌纤维素膜作为创伤敷料的可能性.方法:用自制创伤仪于大鼠背部脊柱两侧各制造2.0 cm×2.0 cm大小的皮肤伤口,深及真皮层,两个创面之间间隔1 cm.随机选择一侧为治疗组,表面敷以细菌纤维素膜,另一侧为对照组,敷以油纱布,用1号手术缝线缝扎固定于周围皮肤上.于术后4,7,14,21,28 d观察创面愈合情况,并进行光镜组织学观察.结果与结论:①所有实验动物无死亡.觅食饮水等活动正常,两组均未出现创面感染.②治疗组术后7,14,21,28 d伤口创面愈合率较对照组显著提高.③治疗组肉芽组织层形成较厚,成纤维细胞和血管内皮细胞增生活跃,胶原纤维束增多,真皮层内小血管增生明显.对照组肉芽组织层较薄,成纤维细胞和血管内皮细胞增生不活跃,胶原纤维含量较治疗组少,小血管数量少.结果提示细菌纤维素膜对皮肤创伤性损伤具有促进愈合和抗感染的作用.     

人工肺的膜材料:研究与应用

背景:人工肺是一项生命支持技术,可以在自身肺功能出现衰竭不能维持人体器官充分的氧供时使用,或者从长远发展来看,可永久性地植入人体,部分或完全替代人体肺功能。当前,通过改进膜材料、优化设计以及对各种性能的实验评估和临床评价,人工肺的研究着力于提高气体交换能力和生物相容性,为抢救患者的生命提供更可靠的手段。目的:利用Scopus数据库及CKNI数据库文献检索和深度分析功能,对人工肺膜材料的文献资料进行多层次探讨分析,根据检索文献结果分析人工肺膜材料的发展状况及趋势。方法:通过计算机检索Scopus数据库及CKNI数据库中2002/2011有关人工肺膜材料的文献,检索词为"人工肺(artificial lung),膜材料(membrane materials),生物相容性(biocompatibility),膜式氧合器(membrane oxygenator),膜式人工肺(membrane-type artificial lung),中空纤维(hollow fiber),高分子材料(polymer materials)"。结果与结论:目前人工肺膜的结构形式已从最初的卷筒式、平板折叠式发展到今天广为采用的微孔中空纤维膜式。用于制造中空纤维的材料主要为一些成纤性能良好的高分子材料,如聚丙烯、聚醚砜等。膜式人工肺可以提高气体交换能力和生物相容性。随着高新材料的开发、基础研究的深入和临床经验的积累,人工肺必将开创治疗重症呼吸系统疾患的新局面。Scopus数据库2002-01/2011-12收录人工肺膜材料的相关文献共172篇,该领域的文献产出量发展较平稳,总体无显著增加,《人工器官》杂志发表文献量最多。     

Designing hydrophobic bacterial cellulose film composites assisted by sound waves

Bacterial cellulose (BC) is a promising material for new technologies, but the range of application is limited due to its hydrophilicity. This work aims to design a hydrophobic material derived from BC, which may find use in a broad range of applications such as packaging, sensing, construction, and electronics. We report that ultrasonic treatment of BC increased the degree of material impregnation into the fiber network that altered the hydrophobic properties of the BC-based composite films. Measurements in XTM revealed that sonication enhanced the porosity of BC films from 5.77% to 22.54%. Materials such as magnesium hydroxide (MH), graphene oxide (GO), and stearic acid (SA) were impregnated into the BC films. FTIR analysis and SEM-EDS confirmed the absorption of these molecules into the BC fibers. The water contact angle (WCA) of BC films impregnated with these functional materials showed a three to four-fold increase in hydrophobicity. The incorporation of 0.3% GO in sonicated BC afforded WCA at 137.20°, which is way better than the commercial water repellant (114.90°). The sonicated BC film afforded better tensile strength and Young''s modulus, up to 229.67 MPa and 6.85 GPa, respectively. This work has shown that ultrasonic treatment improved the absorption capability of BC towards hydrophobic functionalization.

Ultrasonic treatment of bacterial cellulose increased the degree of material impregnation such as graphene oxide into the fiber network that altered the hydrophobic properties of the BC-based composite films.     

呼吸机膜材料的选择及其生物相容性

背景：随着医学和组织工程技术发展,各种生物材料相继出现,如何选择合适的膜材料成为人工肺技术发展的关键。目的：评价各种呼吸机膜生物材料的应用性能,寻找合适的呼吸机膜材料。方法：采用电子检索的方式,在万方数据库（http：//www.wanfangdata.com.cn/）中检索1991-01/2011-12有关生物材料应用于呼吸机膜的研究文章,关键词为＂膜式,人工肺,生物材料＂。排除内容重复、普通综述及Meta分析类文章。共纳入20篇文献进行评价,中文文献11篇,英文文献9篇。结果与结论：目前人工肺膜的结构形式已从最初的卷筒式、平板折叠式发展到今天广为采用的微孔中空纤维膜式。用于制造中空纤维的材料主要为一些成纤性能良好的高分子材料,如聚丙烯、聚醚砜等。膜式人工肺可以提高气体交换能力和生物相容性。随着高新材料的开发、基础研究的深入和临床经验的积累,人工肺必将开创治疗重症呼吸系统疾患的新局面。     

Preparation of Ni/C porous fibers derived from jute fibers for high-performance microwave absorption

Composites obtained by incorporating magnetic nanoparticles into porous carbon materials are promising in serving as microwave absorbing materials. In this study, Ni/C porous fibers were successfully synthesized through a simple in situ template method by using low-cost jute fibers as carbon source and template. The results showed that the Ni nanoparticles were uniformly loaded on the surface and hollow porous structure of the Ni/C porous fibers. Meanwhile, the content and size of the Ni nanoparticles on the Ni/C porous fibers can be controlled. Due to a suitable filling content, the synergistic effect of dielectric loss, interface polarization loss, magnetic loss and porous structure of the Ni/C porous fibers, an excellent microwave absorption performance was achieved. The minimum reflection loss value reached −43.0 dB, and a reflection loss value less than −10 dB was in the frequency range of 11.2–16.1 GHz with 2.0 mm thickness. In particular, under matching thickness (1.5–3.5 mm), the values of all the reflection loss peaks were below −20.0 dB. It is believed that this work can not only provide a new way to design excellent carbon-based microwave absorbing materials, but also offer an effective design strategy to synthesize biomass nanocomposites.

Ni/C porous fibers derived from jute fibers exhibited excellent microwave absorption performance.     

Application of blocking and immobilization of electrospun fiber in the biomedical field

The fiber obtained by electrospinning technology is a kind of biomaterial with excellent properties, which not only has a unique micro–nanostructure that gives it a large specific surface area and porosity, but also has satisfactory biocompatibility and degradability (if the spinning material used is a degradable polymer). These biomaterials provide a suitable place for cell attachment and proliferation, and can also achieve immobilization. On the other hand, its large porosity and three-dimensional spatial structure show unique blocking properties in drug delivery applications in order to achieve the purpose of slow release or even controlled release. The immobilization effect or blocking effect of these materials is mainly reflected in the hollow or core–shell structure. The purpose of this paper is to understand the application of the electrospun fiber based on biodegradable polymers (aliphatic polyesters) in the biomedical field, especially the immobilization or blocking effect of the electrospun fiber membrane on cells, drugs or enzymes. This paper focuses on the performance of these materials in tissue engineering, wound dressing, drug delivery system, and enzyme immobilization technology. Finally, based on the existing research basis of the electrospun fiber in the biomedical field, a potential research direction in the future is put forward, and few suggestions are also given for the technical problems that urgently need to be solved.

The unique blocking and immobilization of electrospinning nanofibers play an important role in tissue engineering, wound dressings, drug delivery systems and other fields.     

牛煅烧骨颗粒复合骨水泥的生物力学性能评定

目的分析不同质量比的牛煅烧骨颗粒复合骨水泥结构特征及生物力学性能.方法把提取过bBMP的牛骨颗粒制成煅烧骨,以不同的质量比与骨水泥混合制成复合材料,测定其生物力学性能与电镜下结构.结果复合材料呈均匀混合分布并多点状结合,其中存在较多的裂隙;含牛煅烧骨颗粒质量比为500mg/g的复合材料的生物力学性能最为适宜.结论牛煅烧骨颗粒复合骨水泥后具有新骨长入的通道,含煅烧骨质量比为500mg/g的复合材料生物力学性能良好,能作为支架材料修复骨缺损.     

The facile synthesis and bioactivity of a 3D nanofibrous bioglass scaffold using an amino-modified bacterial cellulose template

Porous bioglass (BG) scaffolds are of great importance in tissue engineering because of their excellent osteogenic properties for bone regeneration. Herein, we reported for the first time the use of amino-modified bacterial cellulose (NBC) as a template to prepare a three-dimensional (3D) nanofibrous BG scaffold by a facile modified sol–gel approach under ultrasonic treatment. The results suggested that the amino groups on the BC template could effectively promote the absorption of the deposited CaO and SiO₂ precursors, and the as-obtained BG scaffold showed a 3D interconnected porous network structure consisting of nanofibers with a diameter of about 20 nm. Furthermore, the as-obtained BG scaffold showed very good bioactivity after being immersed in SBF for 7 days. This research provides a facile and efficient way to prepare a nanofibrous BG scaffold with 3D porous structure, which can be used as a promising candidate for biomedical applications.

A nanofibrous BG scaffold with a high quality 3D porous interconnected structure has been prepared via a facile modified sol–gel approach using amino-modified bacterial cellulose as the template.     

优化磷酸三钙/聚磷酸钙纤维/聚乳酸软骨组织工程支架材料的配比

背景：前期实验显示,聚乳酸存在刚度差,降解缓慢,降解后期降解液明显偏于酸性,易在细胞培养时引起无菌性炎症反应等缺点。目的：在前期工作的基础上,优化聚乳酸支架材料实验方案和配比。方法：自制聚磷酸钙纤维和β-磷酸三钙为添加材料,聚左旋乳酸为基体材料,采用溶媒浇铸/粒子滤取技术与气体发泡相结合制备配比20/30/50磷酸三钙/聚磷酸钙纤维/聚乳酸软骨组织工程支架复合材料。结果与结论：①磷酸三钙/聚磷酸钙纤维/聚乳酸支架材料具有三维、连通、微孔网状结构,孔隙率在70%～95%。②孔隙率相近时,该支架材料的压缩模量比纯聚乳酸支架的压缩模量有了明显提高。③支架材料的降解率可通过加入聚磷酸钙纤维和支架的孔隙率加以调控。④β-磷酸三钙的加入使降解液pH值保持在6.0～7.0之间,避免了酸性降解产物引起的无菌性炎症反应。说明磷酸三钙/聚磷酸钙纤维/聚乳酸支架材料的物理力学性能和降解性能基本满足软骨组织工程的要求。     

Bacterial cellulose modified with xyloglucan bearing the adhesion peptide RGD promotes endothelial cell adhesion and metabolism--a promising modification for vascular grafts

Today, biomaterials such as polytetrafluorethylene (ePTFE) are used clinically as prosthetic grafts for vascular surgery of large vessels (>5 mm). In small diameter vessels, however, their performance is poor due to early thrombosis. Bacterial-derived cellulose (BC) is a new promising material as a replacement for blood vessels. This material is highly biocompatible in vivo but shows poor cell adhesion. In the native blood vessel, the endothelium creates a smooth non-thrombogenic surface. In order to sustain cell adhesion, BC has to be modified. With a novel xyloglucan (XG) glycoconjugate method, it is possible to introduce the cell adhesion peptide RGD (Arg-Gly-Asp) onto bacterial cellulose. The advantage of the XG-technique is that it is an easy one-step procedure carried out in water and it does not weaken or alter the fiber structure of the hydrogel. In this study, BC was modified with XG and XGRGD to asses primary human vascular endothelial cell adhesion, proliferation, and metabolism as compared with unmodified BC. This XG-RGD-modification significantly increased cell adhesion and the metabolism of seeded primary endothelial cells as compared with unmodified BC whereas the proliferation rate was affected only to some extent. The introduction of an RGD-peptide to the BC surface further resulted in enhanced cell spreading with more pronounced stress fiber formation and mature phenotype. This makes BC together with the XG-method a promising material for synthetic grafts in vascular surgery and cardiovascular research.     

Preparation and properties of PTFE hollow fiber membranes for the removal of ultrafine particles in PM2.5 with repetitive usage capability

This study reveals the first attempt to apply PTFE hollow fiber membranes for removing ultrafine particles in PM_2.5. The asymmetric polytetrafluoroethylene (PTFE) hydrophobic hollow fiber membranes were prepared through a cold pressing method including paste extrusion, stretching and heating. The reduction ratio, stretching ratio and heating temperature have influences on the morphology, structure, porosity, shrinkage ratio, tensile strength and permeability of the PTFE hollow fiber membranes. The morphological properties of the PTFE hollow fiber membrane were studied using field emission scanning electron microscopy (FESEM). The increase of stretching ratio can improve the pore size and porosity of the hollow membrane, but be negative for the mechanical properties. By changing the reduction ratio we can obtain different inner diameter PTFE hollow fiber membranes. Finally, the PTFE hollow fiber membranes were tested for their performances in the removal of ultrafine particles in PM_2.5. The PTFE hollow fiber membranes had the microstructure of nodes interconnected by fibrils, designed to possess the synergistic advantages of porous filters and fibrous filters with a sieve-like outer surface and a fibrous-like porous substrate. Under dead-end filtration, the filtration efficiency is related to the wall thickness, pore size and porosity of the membranes. The air filtration achieved was higher than 99.99% for PM_2.5 and 90% for PM_0.3, indicating that all the prepared PTFE hollow fiber membranes exhibited satisfactory removal of ultrafine particles performances. Because of the hydrophobicity, PTFE hollow fiber membranes have self-cleaning ability and a large dust-holding capacity of >120 g m⁻², slowing down membrane fouling. The fouled filter media after washing retained a high filtration efficiency without obvious deterioration. The hydrophobic PTFE hollow fiber membranes developed in this work exhibited potential applications in air filtration.

This study reveals the first attempt to apply PTFE hollow fiber membranes for removing ultrafine particles in PM_2.5.